Navigation Links
Brain waves encode information as time signals
Date:12/16/2013

How information is processed and encoded in the brain is a central question in neuroscience, as it is essential for high cognitive function such as learning and memory. Theta-gamma oscillations are "brain waves" observed in the hippocampus of behaving rats, a brain region involved in learning and memory. In rodents, theta-gamma oscillations are associated with information processing during exploration and spatial navigation. However, the underlying synaptic mechanisms have so far remained unclear. In research published this week in the journal Neuron, postdoc Alejandro Perna-Andrade and Professor Peter Jonas, both at the Institute of Science and Technology Austria (IST Austria), discovered the synaptic mechanisms underlying oscillations at the dentate gyrus (main entrance of the hippocampus). Furthermore, the researchers suggest a role for these oscillations in the coding of information by the dentate gyrus principal neurons. Thus, these findings contribute to a better understanding of how information is processed in the brain.

Brain oscillations are, in fact, rhythmic changes in voltage in the extracellular space, referred to as electrical brain signals associated with the processing of information. These electrical signals are similar to those seen in electro-encephalographic recordings (EEG) in humans. Perna-Andrade and Jonas observed these oscillations in a brain region called the hippocampus in behaving rats, and recorded oscillations occurring in this area using extracellular probes. To understand how oscillations are generated and which synaptic events trigger these oscillations, the researchers looked at synaptic transmission in granule cells (principal cells at the main entrance of the hippocampus) from both the extracellular (oscillations) and the intracellular perspectives (synaptic currents and neuronal firing), and then correlated the two. They discovered that excitatory and inhibitory synaptic signals contributed to different frequencies of oscillations, with excitation from the entorhinal cortex generating theta oscillations and inhibition by local dentate gyrus interneurons generating gamma oscillations. Together, excitation and inhibition provide the rhythmic signals of oscillations. It has been speculated that oscillations may help the dentate gyrus to encode information by acting as reference signals in temporal coding. Perna-Andrade and Jonas now show that granule cell neurons send signals only at specific times in the cycle of oscillations. This so-called "phase locking" is necessary if oscillations are to function as reference signals in temporal coding.

The precise, high-resolution recording from granule cells necessary for these discoveries was possible only through technological innovations by Perna-Andrade and Jonas, as previously no equipment was available to record synaptic signals in active rats in such high resolution. They are the result of a collaboration with the Miba machine shop, IST Austria's electrical and mechanical SSU (Scientific Service Unit). Adapting commercially available equipment and custom-designing tools, Perna-Andrade, Jonas and Todor Asenov, manager of the Miba machine shop, produced the first tools for precise biophysical analysis in active rats. This research is therefore not only a scientific advance but also represents a significant technological and conceptual progress in the quest to understand neuronal behavior under natural conditions.


'/>"/>

Contact: Oliver Lehmann
oliver.lehmann@ist.ac.at
43-022-439-000-1006
Institute of Science and Technology Austria
Source:Eurekalert  

Related biology news :

1. Study breaks blood-brain barriers to understanding Alzheimers
2. Dietary amino acids improve sleep problems in mice with traumatic brain injury
3. Gene found to be crucial for formation of certain brain circuitry
4. TGen, Barrow and PCH receive $4 million grant to study genetic basis of brain injuries
5. Alzheimers risk gene may begin to affect brains as early as childhood, CAMH research shows
6. New compound for slowing the aging process can lead to novel treatments for brain diseases
7. Neurofeedback tunes key brain networks, improving subjective well-being in PTSD
8. Prenatal exposure to alcohol disrupts brain circuitry
9. New UK study suggests low vitamin D causes damage to brain
10. An abnormal resting-state functional brain network indicates progression towards AD
11. Swarming insect provides clues to how the brain processes smells
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Brain waves encode information as time signals
(Date:8/23/2017)... -- The general public,s help is being enlisted in what,s thought to be ... on the human body –and are believed to affect health.  ... The Microbiome Immunity Project is the largest study ... gut. The project's goal is to help advance scientific knowledge of the ... ...
(Date:6/30/2017)... , June 30, 2017 Today, ... developer and supplier of face and eye tracking ... Featured Product provider program. "Artificial ... innovative way to monitor a driver,s attentiveness levels ... from being able to detect fatigue and prevent ...
(Date:5/23/2017)...  Hunova, the first robotic gym for the rehabilitation and functional motor ... Genoa, Italy . The first 30 robots will be ... USA . The technology was developed and patented at the ... spin-off Movendo Technology thanks to a 10 million euro investment from entrepreneur ... ...
Breaking Biology News(10 mins):
(Date:10/10/2017)... ... October 10, 2017 , ... ... targeted antibody-drug conjugate (ADC) therapeutics, today confirmed licensing rights that give it ... Nanoparticle), a technology developed in collaboration with Children’s Hospital Los Angeles (CHLA). ...
(Date:10/10/2017)... ... October 10, 2017 , ... ... process optimization firm for the life sciences and healthcare industries, announces a presentation ... San Francisco. , The presentation, “Automating GxP Validation for Agile Cloud Platforms,” will ...
(Date:10/9/2017)... Arizona (PRWEB) , ... October 09, 2017 , ... ... Kindred, a four-tiered line of medical marijuana products targeting the needs of consumers ... and packaging of Kindred takes place in Phoenix, Arizona. , As operators of ...
(Date:10/6/2017)... ... October 06, 2017 , ... ... healthcare and technology sector at their fourth annual Conference where founders, investors, innovative ... speakers and the ELEVATE pitch competition showcasing early stage digital health and med ...
Breaking Biology Technology: